Electrical distribution equipment in all voltage classes often has ventilation openings to permit the circulation of air by convection within the enclosure. These electronic vents help to maintain component temperatures inside the enclosure within certain design limits.

Most solar energy vents operate exactly like regular vents, but instead of being powered by the wind, they generate energy from the sun. A regular wind-driven vent will not operate on a hot, still summer day. A solar vent will work all year round.

http://www.srlvents.com/adhesive-vents/electronic-vents/